Today's engine systems are often equipped with one or more turbochargers, an exhaust gas circulation system and electronically controlled valves in the exhaust system to control compressor bypass pathways, turbine bypass pathways, mass flow rate of exhaust gas recirculated and other known control features. An exhaust pathway that avoids the turbine is often controlled by what is termed in the art as a wastegate valve. For instance, when boost pressure approaches some predetermined maximum or there is a risk of turbine overspeed, the wastegate valve may be opened to channel exhaust directly from the exhaust manifold toward the tailpipe, without imparting energy to the turbocharger. Due to varying temperatures and the constituents in the engine exhaust, these valves can accumulate a build-up of hydrocarbons, soot and other compounds that inhibit proper operation to the extent that the valve can sometimes be stuck closed. In an effort to prevent valves located in the exhaust system from becoming stuck closed, the art recognizes various strategies for exercising the valve to inhibit sticking. For instance, U.S. Patent Publication 2009/0164106 teaches opening and closing an EGR valve when the engine ignition is on but the engine is not running in order to inhibit sticking after the engine begins operation. While maybe not true for all valves, such as valves controlling exhaust gas recirculation, a stuck closed wastegate valve can potentially lead to catastrophic turbocharger or engine failure.
The present disclosure is directed toward one or more of the problems set forth above.